U.S. Pat. No. 5,538,607 in the name of Ray H. Pate describes Hall-Heroult technology for the production of molten metal, specifically molten aluminum, utilizing carbon blocks and associated anode bars, cathode bars etc. Such collector bars, be they an anode bar or cathode bar, are subject to rapid consumption necessitating refurbishment and/or replacement costing millions of dollars. In the Pate U.S. Pat. No. (5,538,607) an anode assembly is disclosed in which an anode bar is housed in a metal sleeve of relatively hard electrically conductive material, though the conductivity is less than the higher relative electrical conductivity of the copper anode bar. However, the harder outer metal sleeve resists consumption during use while facilitating current flow in as efficient a manner as possible. Thus, though the patent to Pate provides a novel long lasting slow consuming anode assembly, the industry lacks a cathodic current collector which is as efficient and long lasting.
Moreover, cathode collectors remain costly from a fabrication standpoint, as is perhaps best evidenced by the multi-pieced cathodic current collector disclosed in U.S. Pat. No. 3,551,319 in the name of Charles H. Elliott. This patent discloses a cathodic current collector formed by an L-shaped or U-shaped ferrous material sheath which houses a copper core and is closed by one or more ferrous blocks, all of which are welded to each other and are suitably installed in tile cell lining of a conventional reduction cell spaced about and supported by a plurality of carbon blocks. The copper core reduces resistance to achieve efficient current flow, whereas the current sheath affords shielding/protection. However, the cost of fabrication of the relatively complex cathodic collector is quite high due to both the cost of materials involved, as well as the assembly thereof.